1. Field of the Invention
The present invention is generally directed toward vehicle heating, ventilation, and air conditioning control systems and, more specifically, toward such control systems.
2. Description of Related Art
Vehicle heating, ventilation, and air conditioning systems (hereafter HVAC systems) have conventionally included components and vents located in or around the dashboard. However, as is well known to anyone who has been in a vehicle having a conventional HVAC system, there is a significant difference in temperature between the front portion (hereinafter front cabin) and the rear portion (hereinafter rear cabin) of the cabin, especially on days with extreme conditions (hot, sunny days and cold days). Providing all of the vents at the front of the vehicle usually maintains uncomfortable temperature conditions for occupants in the rear cabin. Alternatively, if an effort is made to make the rear occupants comfortable, the front occupants are over-heated or over-cooled.
Accordingly, rear HVAC systems and controls in the rear cabin, which are in addition to the conventional front HVAC systems and controls in the front cabin, have been developed. Such vehicle HVAC control systems include parallel front and rear HVAC control panels connected to a controller.
In the conventional HVAC control system, the rear HVAC system is operable via input from either the rear control panel or the front control panel. The rear HVAC system can be controlled via input from the front control panel, but can only be controlled via input from the rear control panel when permitted by the front control panel through actuation of the rear manual button on the front control panel. When the rear manual button is not actuated, the rear HVAC system is controlled via input from the front control panel. However, when the rear manual button is actuated, the rear HVAC system is controlled via input from the rear control panel.
Further, with the conventional HVAC control system, the rear manual button on the front control panel is automatically de-actuated every time the vehicle is turned off. Accordingly, for the rear HVAC system to be controlled via input from the rear control panel, the rear manual button must be actuated by the front occupant every time the vehicle is started. This standard resetting procedure ensures that subsequent to restarting of the vehicle, occupants of the front cabin only intentionally relinquish control of the rear HVAC system to the rear control panel. Clearly, it is futile to give control of the rear HVAC system to the rear control panel if the rear cabin is unoccupied. Therefore, by de-actuating the rear manual button when the vehicle is turned off and thus deactivating the rear control panel, the rear HVAC system is not inadvertently controlled by the rear control panel after the vehicle is restarted. This is especially useful when there are no occupants in the rear cabin after the vehicle is restarted.
However, the foregoing conventional HVAC control system suffers from a number of disadvantages. For example, when occupants are still present in the rear cabin after the vehicle restart, the rear manual button must again be actuated to allow control of the rear HVAC system by input from the rear control panel. Having to actuate the rear manual button after every restart can be inconvenient for the front cabin occupant. Furthermore, waiting for the rear manual button to be actuated can be annoying for the rear cabin occupant.
Therefore, there exists a need in the art for a vehicle HVAC control system that provides rear occupants with improved control over the rear HVAC system.